1. Field of the Invention
The present invention is in the field of index marking and particularly dry transfer index marking means.
2. The Prior Art
In certain fields, e.g. architecture, illustration, design, engraving, etc., artistic representations are frequently made on two or more superimposed sheets whereby the representations or components appearing on the superimposed sheets bear a specific positional relation to each other. Subsequently, the sheets bearing the various components of the design are separated, for instance in order to make separate photographs of the sheets as an element of a three color engraving process. Thereafter, to secure a finished picture or design, it is necessary that the photographs, etchings or projections thereof be aligned in precise superimposed relation.
To facilitate such repositioning, it is conventional to mark each of the layers with index marks, such as an X, a circle, etc., while the same are still superimposed. Initially, the application of such index marks was a time-consuming procedure, involving manually accurately adjusting the position of a subsequent index mark so that it was precisely disposed over an earlier placed mark. The procedure was repeated for each superimposed sheet. Since it is customary to place a multiplicity of registering index marks at various locations on the superimposed sheets, a substantial amount of time and effort were consumed in the marking operation.
In accordance with my U.S. Pat. No. 3909,329, there is disclosed an article for substantially accelerating the marking procedure. Briefly, in accordance with such patent, there is provided an article having on its opposed faces, index markings printed in precise register with each other. The device is used by disposing the same between two sheets and rubbing a stylus across the uppermost of the sheets while the lower sheet is supported on a hard surface, whereby index marks are released upwardly and downwardly in precise registry.
While the device in accordance with the noted patent has greatly expedited and facilitated the application of register markings, the manufacture of such device, necessitating as it does an imprinting on opposite surfaces of a single sheet in precise registry, has proved costly to manufacture and has required careful adjustment of the printing facilities.